1. Field of the Invention
The invention is in the field of motorized harvesters having the motor on a ground-supported carrier with a rotatable blade mounted on the motor shaft, and the motorized vehicles of this type are the common and widely used self-propelled lawn mowers in which a novel provision is made for removing debris and cut clippings which accumulate on the underside of the deck by means of flexible metal pin attachments secured in symmetrical fashion to the cutter blade about the motor shaft opening thereof and at a critical spacing from the deck. The invention includes novel attachment means for the pins to the cutter blade.
2. Description of the Prior Art
In the prior art the patent to Brown, U.S. Pat. No. 2,957,295, and the patent to Johnson, U.S. Pat. No. 3,396,518, each teaches the concept for cleaning cut grass from the underside of the housing of rotary mower by bringing a scraper into direct contact with the underside. The scraper is a second element mounted on a common shaft with the blade. If the housing is flat as shown in Johnson and Brown, then there is no problem with the scraper doing its job, but the housing in most commercial moweres are not flat. Instead, they are curved as shown in the patent to Phillips, Jr. et al, U.S. Pat. No. 2,953,888. It is an essential requirement in Brown that the Brown end elements 19, which are curved and act as air scoops to blow away the grass clippings out of the chute 22 at the top of the mower. This pair of upstanding metal elements 19, which are bolted or riveted to the ends of the blade 11, has as the only function an air pumping action, because of the inclined air deflecting surface at 13 (see column 3 of Browm, lines 5 -- 18).
The significant difference of the present invention over Brown and Johnson is that a single blade is used instead of two blades. The separate blade for scraping the ceiling of the housing has never been used because most housings are curved and because when stones are picked up by the blade, they jam the cleaning blade.
There is no concept in these prior art patents for the mounting of non-cutting pins as well as non-scraping pins, which do not come into contact with the underside of the housing, but rather come into contact with clippings of grass or debris which cling to the underside of the housing.
There is further no teaching in the prior art of a further critical limitation that the tip of the flexibly mounted pin be spaced from the surface of the housing underside by 1/4 inch + or - 1/16 inch and that a pair of equally spaced pins on each side of the center shaft mounting opening can completely prevent the building up of clippings or debris on the underside of the housing.